Pump.



R. N. STEWART.

PUMP. APPLICATION FILED MAR. 22, ma.

1,209,065.. Patented Dec. 19,1916.

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ROY N. STEWART, OF DORCHESTEIR, MASSACHUSETTS.

PUMP.

Specification of Letters Patent.

Patented Dec. 19, 1916.

I Application filed March 22, 1913. Serial No. 756,090. i

To all whom it may concern Be it known that I, ROY N. STEWART, a citizen of the United States, residing at Dorchester, county of Suffolk, Commonwealth of Massachusetts, have invented certain new I and useful Improvements in Pumps, of

' which the following is a specification.

Thisinvention relates to pumps and particularly to a pump for variable water levels. In pumps of this class, which are particularly designed for irrigating purposes, it is necessary to have the same operative and effective at a variety of levels in the source of supply, The condition of the usual snipply varies widely and Inuch'practical di culty has been experienced inv finding a pump which will operate successfully under the most adverse conditions.

To this end I have devised my present inventionin which I provide dual elements on a single shaft, one working auxiliary to the other and creating a working level for the main impeller when such does not naturally exist, in order that the supply may be had with certainty. 1

The construction and principle of my inve'ntion will he more fully disclosed invthe specification which follows, and as illustrative of the same I have shown in the annexed drawings an embodiment which I have found well adapted for practical purposes.

Throughout specification and drawings like numerals of reference will indicate corresponding parts and in these drawings:

Figure 1'. is a vertical central section through a pump in accordance with my invention, and Fig. 2 is a transverse section on the line 22 of Fig. 1.

I have indicated at 1 a base or foundation from which rises a casing 2 having alateral flange 3 at its top which rests on supports A vertical 4 of any suitable construction. shaft 5 is journaled in a step bearing 6v at its lower end and in a thrust bearing 7 at its upper end. Power is applied to the vertical shaft 5 from a driven shaft- 8 by a bevel gear 9 thereon in mesh with a similar gear 10 on said shaft 5. The rotation of the shaft 5 rotates abladed impeller 11, mounted within a guide 12 and fastened on the lower end of said shaft near the bottom of the casing. A pair of gate valves 13 are hinged on opposite sides of the casing and control passages 14 between the walls of the cas ng and the impeller. The upper bladed 1mpeller 15 on shaft 5 is of larger diameter overcomes the difliculties incident to a than the lower impeller 11 and its guide 16 is secured to the casing. I

The operation is as follows: The shaft 5 [is rotated through the-gears 9 and 10 and to the-impeller blades 11 the water level in thecasimparts rotation and 15. Should ing-be sufficiently high to provide an effective working area for the impeller 15, it will operate to lift the water from the casing. In this event, the gates.13 open freely, but when the water level is so low as notto fill the water chamber between the two impellers, the valves will remain closed until the auxiliary impeller 11 has forced the water through the passages 14 into the chamber above it. This new water level thus createdofi'ers an efl'ective'working area for the impeller 15 to become effective and raise the column for the delivery. This action is entirely automatic and in apractical var-iable level.

Various modifications in the'construction and form of my invention, coming within its spirit and scope, may obviously be resorted to if found within the limits of the appended claims.

What I, therefore, claim and desire to secure by Letters Patent is: v

1. In a variable level pump, a casing hav-- ing a chamber, a shaft in said casing, a main impeller on said shaft in effective working relation to said chamber, auxiliary means to initially fill said chamber including an element rotatably but not longitudinally movable upon said shaft, and a valve associated with said auxiliary means and automatieally'becoming effective to permit said auxiliary means to create a new fluid level in said chamber whenever the effective working area therein is insufficient for the needs of the main impeller. g

2. In a variable level pump, a casing having a chamber, impeller on said shaft in effective working relation to said chamber, an auxiliary impeller rotatably but not longitudinally movable upon said' shaft and adapted to ini-' tially fill said chamber, with said auxiliary impeller and automatically becoming efi'ective to permit said impeller to create a new fluid level in said chamber whenever the effective working area therein is insufficient the main impeller.

3. In a-pump of the class described, a

way

a shaft in said casing, a main 1 0 and means associated 1 for the needs of shaft, a main impeller thereon, a casing in which said shaft is mounted, said casing having a chamber in effective working relation to said impeller, an auxiliary impeller on said shaft, and gate valves cooperating with said auxiliary impeller to initially fill said chamber.

4. In a variable level pump of the class described, a casing having a liquid chamber, a shaft in said casing, a pair of spaced impellers on said shaft, and means cooperating with one of said impellers to initially fill said chamber and automatically becoming effective to create a new fluid level when the effective working area in the chamber is insufiicient for the needs of the main impeller.

5. In a variable level pump, a casing, a shaft rotatable therein, a main impeller on said shaft, an auxiliary impeller on said shaft defining with said main impeller and the casing an intermediate chamber arranged ineifective working relation to the main impeller, and means cooperating with said auxiliary impeller to initially fill said chamber and automatically becoming effective to create anew fluid level whenever the effective working area in said chamber is insufficient for the needs of the main im-' peller.

6. In a varlable level pump, a'casing, a shaft rotatable therein, a main impeller on said shaft, anauxiliary impeller on said shaft defining with said main impeller and the casing an intermediate chamber ar-,

rangedin effective working relation to the main impeller, and gate valves cooperating with said auxiliary impeller to initially fill said chamber and automatically becoming effective to create a new fluid level Whenever the effective working area insaid chamber is insufficient for the needs of the main impeller.

7. In a variable level pump, a casing, a shaft rotatable therein, a pair of spaced members in said casing having openings for the passage of a fluid and defining 'an intermediate chamber, a pair of impellers mounted on said shaft in effective relation to the fluid openings through said members, one of said members having an auxiliary fluid opening and a valve controlling said opening and cooperating with the impeller associated with said member to initially fill said chamber and coming effective to permit said lmpeller to create a new fluid level in said chamber said valve automatically beis insufficient for the needs of the other impeller.

8. In a variable level pump, a casing, a shaft rotatable therein, a pair of spaced members in said casing having openings for the passageof a fluid and defining an intermediate chamber, a pair of impellers mounted on said shaft in eflective relation to the fluid openings through said members, and means cooperating with one of said impellers to initially fill said chamber and automatically becoming eflective to permit said impeller to create a new fluid level in said chamber whenever the effective working area therein is insuflicient for the needs of the other impeller.

In testimony whereof I afix my signature in presence of two witnesses.

VICTORIA LownEN, MARION C. HOBBS. 

